The development of an evanescent wave biosensor enabling the monitoring of binding interactions of small weakly interacting bio-molecules (MW<100Da) currently not possible is proposed. This technique relies on an innovative transducer design employing a novel self-compensating interferometer capable of surface sensitivities at the level of fg/mm2 - many orders of magnitude improvement over commercially available biosensors. The device employs the novel use of microfluidic flow dynamics for high capture efficiency further reducing the time to results for high throughput and is readily integrated into a small disposable, sealed cartridge for ease of use and low cost. The Phase I effort is focused around a proof-of-principle experiment demonstrating the sensitivity of the device. The Phase II effort will focus on the development of a microfluidic flow cell and a technical demonstration of the binding of a relevant ligand-protein system. [unreadable] [unreadable]